西藏冈底斯带中部南木林地区林子宗群火山岩锆石U-Pb年龄和地球化学特征
|
摘要
林子宗群火山岩广泛分布在冈底斯带上,其岩石学特征及所代表的区域不整合事件被认为与特提斯洋俯冲消减到印度-亚洲大陆碰撞转变有关。对冈底斯带南木林地区的林子宗群火山岩进行了LA-ICP-MS锆石U-Pb测年及地球化学研究,获得林子宗群火山岩帕那组LA-ICP-MS锆石U-Pb年龄为46.08±0.47Ma、49.00±1.30Ma,对比冈底斯带其他地区已发表的年龄数据,认为印度-亚洲大陆碰撞(在西藏南部)的时间,东部可能依次早于中部和西部。地球化学特征表明,冈底斯带南木林地区林子宗群火山岩具有碰撞后地壳加厚背景下产生的弧火山岩特征,应为新特提斯洋俯冲消减到印度-亚洲大陆碰撞构造背景下形成的。
The volcanic rocks of Linzizong Group are widely distributed in the Gangdise belt. Their petrological characteristics together with regional unconformity events are considered to be related to the transform from Tethys Ocean subduction to the collision of Indian-Asian continent. In this paper, LA-ICP-MS zircon U-Pb age and geochemistry were investigated for the volcanic rocks in Linzizong Group, and the result indicates that the LA-ICP-MS zircon U-Pb ages of Pana Formation volcanic rocks of Linzizong Group are 46.08 ± 0.47 Ma and 49.00 ± 1.30 Ma. Compared with the related age data of other regions of the Gangdese belt, the authors hold that the time of the India-Asia continent collision(in southern Tibet) in the eastern part may be earlier than that of the central and western regions. Additionally, the geochemical characteristics show that the Linzizong volcanic rocks were generated under the background of the crustal thickening after collision in the Nanmulin area of Gangdese belt, and were formed in the background from the transform from the new Tethys Ocean subduction to the collisional structure of the Indian-Asian continent.
The volcanic rocks of Linzizong Group are widely distributed in the Gangdise belt. Their petrological characteristics together with regional unconformity events are considered to be related to the transform from Tethys Ocean subduction to the collision of Indian-Asian continent. In this paper, LA-ICP-MS zircon U-Pb age and geochemistry were investigated for the volcanic rocks in Linzizong Group, and the result indicates that the LA-ICP-MS zircon U-Pb ages of Pana Formation volcanic rocks of Linzizong Group are 46.08 ± 0.47 Ma and 49.00 ± 1.30 Ma. Compared with the related age data of other regions of the Gangdese belt, the authors hold that the time of the India-Asia continent collision(in southern Tibet) in the eastern part may be earlier than that of the central and western regions. Additionally, the geochemical characteristics show that the Linzizong volcanic rocks were generated under the background of the crustal thickening after collision in the Nanmulin area of Gangdese belt, and were formed in the background from the transform from the new Tethys Ocean subduction to the collisional structure of the Indian-Asian continent.
引文
[1]李光明,段志明,黄勇,等西藏冈底斯-喜马拉雅地质与成矿[M].武汉:中国地质大学出版社,2017:62.
[2]莫宣学,赵志丹,邓晋福,等.印度-亚洲大陆主碰撞过程的火山作用响应[J].地学前缘,2003,10(3):135-148.
[3]莫宣学,赵志丹,朱弟成,等.西藏南部印度-亚洲碰撞带岩石圈:岩石学-地球化学约束[J].地球科学,2009,34(1):17-27.
[4]周肃,莫宣学,董国臣,等.西藏林周盆地林子宗火山岩40Ar/39Ar年代格架[J].科学通报,2004,49(20):2095-2103.
[5]侯增谦,莫宣学,高永丰,等.印度大陆与亚洲大陆早期碰撞过程与动力学模型--来自西藏冈底斯新生代火成岩证据[J].地质学报,2006,80(9):1233-1248.
[6]莫宣学,潘桂棠.从特提斯到青藏高原形成:构造-岩浆事件的约束[J].地学前缘,2006,13(6):43-51.
[7]Mo X,Hou Z,Niu Y,et al.Mantle contributions to crustal thickening during continental collision:Evidence from Cenozoic igneous rocks in southern Tibet[J].Lithos,2007,96(1):225-242.
[8]莫宣学,赵志丹,周肃,等.印度-亚洲大陆碰撞的时限[J].地质通报,2007,26(10):1240-1244.
[9]Hu X M,Wang J G,Wei A N,et al.Constraining the timing of the India-Asia continental collision by the sedimentary record[J].Science China:Earth Science,2017,60(4):603-625.
[10]董国臣,莫宣学,赵志丹,等.拉萨北部林周盆地林子宗火山岩层序新议[J].地质通报,2005,24(6):549-557.
[11]刘鸿飞.拉萨地区林子宗火山岩系的划分和时代归属[J].西藏地质,1993,(2):59-69.
[12]李皓揚,锺孙霖,王彦斌,等.藏南林周盆地林子宗火山岩的时代、成因及其地质意义:锆石U-Pb年龄和Hf同位素证据[J].岩石学报,2007,23(2):493-500.
[13]Lee H Y,Chung S L,Lo C H,et al.Eocene Neotethyan slab breakoff in southern Tibet inferred from the Linzizong volcanic record[J].Tectonophysics,2009,477(1):20-35.
[14]Lee H Y,Chung S L,Ji J,et al.Geochemical and Sr-Nd isotopic constraints on the genesis of the Cenozoic Linzizong volcanic successions,southern Tibet[J].Journal of Asian Earth Sciences,2012,53(2):96-114.
[15]He S,Kapp P,Decelles P G,et al.Cretaceous-Tertiary geology of the Gangdese Arc in the Linzhou area,southern Tibet[J].Tectonophysics,2007,433(1):15-37.
[16]梁银平,朱杰,次邛,等.青藏高原冈底斯带中部朱诺地区林子宗群火山岩锆石U-Pb年龄和地球化学特征[J].地球科学,2010,35(2):211-223.
[17]谢克家,曾令森,刘静,等.藏南昂仁县桑桑地区林子宗群火山岩的形成时代和地球化学特征[J].地质通报,2011,30(9):1339-1352.
[18]于枫,李志国,赵志丹,等.西藏冈底斯带中西部措麦地区林子宗火山岩地球化学特征及意义[J].岩石学报,2010,26(7):2217-2225.
[19]鲍春辉,丁枫,王乾,等.西藏措勤县雄玛地区始新统林子宗群帕那组火山岩地球化学特征及构造背景[J].地质论评,2014,60(2):275-284.
[20]付文春,康志强,潘会彬.西藏冈底斯带西部狮泉河地区林子宗群火山岩地球化学特征、锆石U-Pb年龄及地质意义[J].地质通报,2014,33(6):850-859.
[21]谢冰晶,周肃,谢国刚,等.西藏冈底斯中部孔隆至丁仁勒地区林子宗群火山岩锆石SHRIMP年龄和地球化学特征的区域对比[J].岩石学报,2013,29(11):3803-3814.
[22]李强,冉孟兰,康志强,等.拉萨地块西部亚热区则弄群火山岩锆石U-Pb年龄及其地质意义[J].桂林理工大学学报,2017,37(4):561-569.
[23]刘安琳,朱弟成,王青,等.藏南米拉山地区林子宗火山岩LA-ICP-MS锆石U-Pb年龄和起源[J].地质通报,2015,34(5):826-833.
[24]唐攀,唐菊兴,郑文宝,等.西藏新嘎果地区典中组火山岩年代学、Hf同位素及地球化学特征[J].岩石矿物学杂志,2018,(1):47-60.
[25]Zhu D C,Zhao Z D,Niu Y,et al.The origin and pre-Cenozoic evolution of the Tibetan Plateau[J].Gondwana Research,2013,23(4):1429-1454.
[26]朱弟成,潘桂棠,莫宣学,等.冈底斯中北部晚侏罗世-早白垩世地球动力学环境:火山岩约束[J].岩石学报,2006,22(3):534-546.
[27]潘桂棠,莫宣学,侯增谦,等.冈底斯造山带的时空结构及演化[J].岩石学报,2006,22(3):521-533.
[28]Liu Y S,Hu Z C,Gao S,et al.In situ analysis of major and trace el.ements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J].Chemical Geology,2008,257:34-43.
[29]Ludwig K R.Users manual for Isoplot/Ex:a geochronological toolkit for Microsoft Excel[M].Berkeley:Geochronology Center Special Publication,2003.
[30]吴元保,郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报,2004,49(16):1589-1604.
[31]Chernicoffab C J,Santos J O S,Mcnaughton N J,et al.Combined U-Pb SHRIMP and Hf isotope study of the Late Paleozoic YaminuéComplex,Rio Negro Province,Argentina:Implications for the origin and evolution of the Patagonia composite terrane[J].Geoscience Frontiers,2013,4(1):37-56.
[32]Hugh R Rollison著.杨学明,杨晓勇,陈双喜,译.岩石地球化学[M].合肥:中国科学技术大学出版社,2000.
[33]Zhao Z D,Mo X X,Zhang S Q,et al.Post-collisional magmatism in Wuyu basin,central Tibet:evidence for recycling of subducted Tethyan oceanic crust[J].Science in China,2001,44(S1):27-34.
[34]Coulon C,Maluski H,Bollinger C,et al.Mesozoic and cenozoic volcanic rocks from central and southern Tibet:39Ar-40Ar dating,petrological characteristics and geodynamical significance[J].Earth&Planetary Science Letters,1986,79(3):281-302.
[35]李再会,郑来林,李军敏,等.冈底斯中部林子宗火山岩40Ar-39Ar年龄及其意义[J].矿物岩石地球化学通报,2009,28(3):223-227.
[36]西蔵自治区地质矿产局.西藏自治区区域地质志[M].北京:地质出版社,1993.
[37]Kang Z Q,Xu J F,Wilde S A,et al.Geochronology and geochemistry of the Sangri Group Volcanic Rocks,Southern Lhasa Terrane:Implications for the early subduction history of the NeoTethys and Gangdese Magmatic Arc[J].Lithos,2014,200/201(1):157-168.
[38]周肃,方念乔,董国臣,等.西藏林子宗群火山岩氩-氩年代学研究[J].矿物岩石地球化学通报,2001,20(4):317-319.
[39]王乔林.冈底斯西部林子宗群火山岩的地球化学特征及锆石年代学研究[D].中国地质大学(北京)硕士学位论文,2011.
[40]He S,Kapp P,Decelles P G,et al.Cretaceous-Tertiary geology of the Gangdese Arc in the Linzhou area,southern Tibet[J].Tectonophysics,2007,433(1):15-37.
[41]刘俊,高顺宝,姜军胜,等.西藏北纳林子宗群火山岩时代、成因及地质意义:锆石U-Pb年代学、Hf同位素与地球化学证据[C]//中国矿物岩石地球化学学会第九次全国会员代表大会暨第16届学术年会文集,2017.
[42]Defant M J,Drummond M S.Drivation of some modern arc magmas by melting of young subducted lithosphere[J].Nature,1990,347(6294):662-665.
[43]Sajona F G,Maury R C,Bellon H,et al.Initiation of subduction and the generation of slab melts in western and eastern Mindanao,Philippines[J].Geology,1993,21(11):1007-1010.
[44]张旗,王焰.埃达克岩的特征及其意义[J].地质通报,2002,21(7):431-435.
[45]张旗.关于C型埃达克岩成因的再探讨[C]//中国科学院地质与地球物理研究所,2012:739-747.
[46]付燕刚,胡古月,高一鸣,等.拉萨地块南木林盆地北缘中新世高锶低钇岩浆作用:锆石U-Pb年龄、Hf同位素和地球化学特征[J].地质论评,2017,63(3):643-658.
[47]莫宣学.青藏高原岩浆岩成因研究:成果与展望[J].地质通报,2009,28(12):1693-1693.
(1)胡敬仁,范跃春,陈国结,等.中华人民共和国区域地质调查报告日喀则市幅(比例尺:1∶250000).西藏自治区地质调查院.2002.
[2]莫宣学,赵志丹,邓晋福,等.印度-亚洲大陆主碰撞过程的火山作用响应[J].地学前缘,2003,10(3):135-148.
[3]莫宣学,赵志丹,朱弟成,等.西藏南部印度-亚洲碰撞带岩石圈:岩石学-地球化学约束[J].地球科学,2009,34(1):17-27.
[4]周肃,莫宣学,董国臣,等.西藏林周盆地林子宗火山岩40Ar/39Ar年代格架[J].科学通报,2004,49(20):2095-2103.
[5]侯增谦,莫宣学,高永丰,等.印度大陆与亚洲大陆早期碰撞过程与动力学模型--来自西藏冈底斯新生代火成岩证据[J].地质学报,2006,80(9):1233-1248.
[6]莫宣学,潘桂棠.从特提斯到青藏高原形成:构造-岩浆事件的约束[J].地学前缘,2006,13(6):43-51.
[7]Mo X,Hou Z,Niu Y,et al.Mantle contributions to crustal thickening during continental collision:Evidence from Cenozoic igneous rocks in southern Tibet[J].Lithos,2007,96(1):225-242.
[8]莫宣学,赵志丹,周肃,等.印度-亚洲大陆碰撞的时限[J].地质通报,2007,26(10):1240-1244.
[9]Hu X M,Wang J G,Wei A N,et al.Constraining the timing of the India-Asia continental collision by the sedimentary record[J].Science China:Earth Science,2017,60(4):603-625.
[10]董国臣,莫宣学,赵志丹,等.拉萨北部林周盆地林子宗火山岩层序新议[J].地质通报,2005,24(6):549-557.
[11]刘鸿飞.拉萨地区林子宗火山岩系的划分和时代归属[J].西藏地质,1993,(2):59-69.
[12]李皓揚,锺孙霖,王彦斌,等.藏南林周盆地林子宗火山岩的时代、成因及其地质意义:锆石U-Pb年龄和Hf同位素证据[J].岩石学报,2007,23(2):493-500.
[13]Lee H Y,Chung S L,Lo C H,et al.Eocene Neotethyan slab breakoff in southern Tibet inferred from the Linzizong volcanic record[J].Tectonophysics,2009,477(1):20-35.
[14]Lee H Y,Chung S L,Ji J,et al.Geochemical and Sr-Nd isotopic constraints on the genesis of the Cenozoic Linzizong volcanic successions,southern Tibet[J].Journal of Asian Earth Sciences,2012,53(2):96-114.
[15]He S,Kapp P,Decelles P G,et al.Cretaceous-Tertiary geology of the Gangdese Arc in the Linzhou area,southern Tibet[J].Tectonophysics,2007,433(1):15-37.
[16]梁银平,朱杰,次邛,等.青藏高原冈底斯带中部朱诺地区林子宗群火山岩锆石U-Pb年龄和地球化学特征[J].地球科学,2010,35(2):211-223.
[17]谢克家,曾令森,刘静,等.藏南昂仁县桑桑地区林子宗群火山岩的形成时代和地球化学特征[J].地质通报,2011,30(9):1339-1352.
[18]于枫,李志国,赵志丹,等.西藏冈底斯带中西部措麦地区林子宗火山岩地球化学特征及意义[J].岩石学报,2010,26(7):2217-2225.
[19]鲍春辉,丁枫,王乾,等.西藏措勤县雄玛地区始新统林子宗群帕那组火山岩地球化学特征及构造背景[J].地质论评,2014,60(2):275-284.
[20]付文春,康志强,潘会彬.西藏冈底斯带西部狮泉河地区林子宗群火山岩地球化学特征、锆石U-Pb年龄及地质意义[J].地质通报,2014,33(6):850-859.
[21]谢冰晶,周肃,谢国刚,等.西藏冈底斯中部孔隆至丁仁勒地区林子宗群火山岩锆石SHRIMP年龄和地球化学特征的区域对比[J].岩石学报,2013,29(11):3803-3814.
[22]李强,冉孟兰,康志强,等.拉萨地块西部亚热区则弄群火山岩锆石U-Pb年龄及其地质意义[J].桂林理工大学学报,2017,37(4):561-569.
[23]刘安琳,朱弟成,王青,等.藏南米拉山地区林子宗火山岩LA-ICP-MS锆石U-Pb年龄和起源[J].地质通报,2015,34(5):826-833.
[24]唐攀,唐菊兴,郑文宝,等.西藏新嘎果地区典中组火山岩年代学、Hf同位素及地球化学特征[J].岩石矿物学杂志,2018,(1):47-60.
[25]Zhu D C,Zhao Z D,Niu Y,et al.The origin and pre-Cenozoic evolution of the Tibetan Plateau[J].Gondwana Research,2013,23(4):1429-1454.
[26]朱弟成,潘桂棠,莫宣学,等.冈底斯中北部晚侏罗世-早白垩世地球动力学环境:火山岩约束[J].岩石学报,2006,22(3):534-546.
[27]潘桂棠,莫宣学,侯增谦,等.冈底斯造山带的时空结构及演化[J].岩石学报,2006,22(3):521-533.
[28]Liu Y S,Hu Z C,Gao S,et al.In situ analysis of major and trace el.ements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J].Chemical Geology,2008,257:34-43.
[29]Ludwig K R.Users manual for Isoplot/Ex:a geochronological toolkit for Microsoft Excel[M].Berkeley:Geochronology Center Special Publication,2003.
[30]吴元保,郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报,2004,49(16):1589-1604.
[31]Chernicoffab C J,Santos J O S,Mcnaughton N J,et al.Combined U-Pb SHRIMP and Hf isotope study of the Late Paleozoic YaminuéComplex,Rio Negro Province,Argentina:Implications for the origin and evolution of the Patagonia composite terrane[J].Geoscience Frontiers,2013,4(1):37-56.
[32]Hugh R Rollison著.杨学明,杨晓勇,陈双喜,译.岩石地球化学[M].合肥:中国科学技术大学出版社,2000.
[33]Zhao Z D,Mo X X,Zhang S Q,et al.Post-collisional magmatism in Wuyu basin,central Tibet:evidence for recycling of subducted Tethyan oceanic crust[J].Science in China,2001,44(S1):27-34.
[34]Coulon C,Maluski H,Bollinger C,et al.Mesozoic and cenozoic volcanic rocks from central and southern Tibet:39Ar-40Ar dating,petrological characteristics and geodynamical significance[J].Earth&Planetary Science Letters,1986,79(3):281-302.
[35]李再会,郑来林,李军敏,等.冈底斯中部林子宗火山岩40Ar-39Ar年龄及其意义[J].矿物岩石地球化学通报,2009,28(3):223-227.
[36]西蔵自治区地质矿产局.西藏自治区区域地质志[M].北京:地质出版社,1993.
[37]Kang Z Q,Xu J F,Wilde S A,et al.Geochronology and geochemistry of the Sangri Group Volcanic Rocks,Southern Lhasa Terrane:Implications for the early subduction history of the NeoTethys and Gangdese Magmatic Arc[J].Lithos,2014,200/201(1):157-168.
[38]周肃,方念乔,董国臣,等.西藏林子宗群火山岩氩-氩年代学研究[J].矿物岩石地球化学通报,2001,20(4):317-319.
[39]王乔林.冈底斯西部林子宗群火山岩的地球化学特征及锆石年代学研究[D].中国地质大学(北京)硕士学位论文,2011.
[40]He S,Kapp P,Decelles P G,et al.Cretaceous-Tertiary geology of the Gangdese Arc in the Linzhou area,southern Tibet[J].Tectonophysics,2007,433(1):15-37.
[41]刘俊,高顺宝,姜军胜,等.西藏北纳林子宗群火山岩时代、成因及地质意义:锆石U-Pb年代学、Hf同位素与地球化学证据[C]//中国矿物岩石地球化学学会第九次全国会员代表大会暨第16届学术年会文集,2017.
[42]Defant M J,Drummond M S.Drivation of some modern arc magmas by melting of young subducted lithosphere[J].Nature,1990,347(6294):662-665.
[43]Sajona F G,Maury R C,Bellon H,et al.Initiation of subduction and the generation of slab melts in western and eastern Mindanao,Philippines[J].Geology,1993,21(11):1007-1010.
[44]张旗,王焰.埃达克岩的特征及其意义[J].地质通报,2002,21(7):431-435.
[45]张旗.关于C型埃达克岩成因的再探讨[C]//中国科学院地质与地球物理研究所,2012:739-747.
[46]付燕刚,胡古月,高一鸣,等.拉萨地块南木林盆地北缘中新世高锶低钇岩浆作用:锆石U-Pb年龄、Hf同位素和地球化学特征[J].地质论评,2017,63(3):643-658.
[47]莫宣学.青藏高原岩浆岩成因研究:成果与展望[J].地质通报,2009,28(12):1693-1693.
(1)胡敬仁,范跃春,陈国结,等.中华人民共和国区域地质调查报告日喀则市幅(比例尺:1∶250000).西藏自治区地质调查院.2002.